How to search for comments ("<!-- -->") using Jsoup?

reference @dlamblin https://stackoverflow.com/a/7541875/4712855 this code get comment html

public static void getHtmlComments(Node node) {
    for (int i = 0; i < node.childNodeSize();i++) {
        Node child = node.childNode(i);
        if (child.nodeName().equals("#comment")) {
            Comment comment = (Comment) child;
            child.after(comment.getData());
            child.remove();
        }
        else {
            getHtmlComments(child);
        }
    }
}

With JSoup 1.11+ (possibly older version) you can apply a filter:

private void removeComments(Element article) {
    article.filter(new NodeFilter() {
        @Override
        public FilterResult tail(Node node, int depth) {
            if (node instanceof Comment) {
                return FilterResult.REMOVE;
            }
            return FilterResult.CONTINUE;
        }

        @Override
        public FilterResult head(Node node, int depth) {
            if (node instanceof Comment) {
                return FilterResult.REMOVE;
            }
            return FilterResult.CONTINUE;
        }
    });
}

When searching you basically use Elements.select(selector) where selector is defined by this API. However comments are not elements technically, so you may be confused here, still they are nodes identified by the node name #comment.

Let's see how that might work:

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Node;

public class RemoveComments {
    public static void main(String... args) {
        String h = "<html><head></head><body>" +
          "<div><!-- foo --><p>bar<!-- baz --></div><!--qux--></body></html>";
        Document doc = Jsoup.parse(h);
        removeComments(doc);
        doc.html(System.out);
    }

    private static void removeComments(Node node) {
        for (int i = 0; i < node.childNodeSize();) {
            Node child = node.childNode(i);
            if (child.nodeName().equals("#comment"))
                child.remove();
            else {
                removeComments(child);
                i++;
            }
        }
    }        
}

Tags:

Java

Jsoup

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